Apparatus for making concrete products

ABSTRACT

An apparatus for mass producing large concrete products, in assembly line manner, on a floor mounted conveyor system, with which various operations are performed at different stations along the conveyor. A sectional mold, for casting purposes, is prepared at a first station and then moved forward. At a second station on the conveyor, the mold is vibrated and filled with concrete, and then moved forward. At a third station, the concrete is completely sealed within the mold, and the mold is elevated, removed from the conveyor, rotated 180*, returned to the conveyor, and stripped from the casting. The casting is then moved along on the conveyor for storage.

I United States Patent 1151 3,659,986 Gelbman [4 1 May 2, 1972 [s41 APPARATUS FOR MAKING CONCRETE 3,528,144 9/1970 Haponski ..2s/41 J PRODUCTS 3,530,970 9/1970 Richardson et al. ..198/20 R [72] Inventor: Nathan L. Gelbman, 1720i N.E. Fourth FOREIGN PATENTS ORAPPLICATIONS Avenue Beach 33 269,! 10/1950 Switzerland ..2s/41 J [22] Filed: Mar. 16, 1970 80,317 l/l956 Netherlands t ,.164/409 [21] Appl' 194538 Primary Examiner-Robert D. Baldwin Attorney-Henry E. Lippert [52] U.S. Cl. ..425/88, i98/l9 R, 425/123,

425/168, 425/432, 425/449, 425/454, 425/424, [57] ABSTRACT 51 1 Cl 425/ An apparatus for mass producing large concrete products, in r' D 2 I assembly line manner, on a floor mounted conveyor system, e o arc R R R with which various operations are performed at different stations along the conveyor. A sectional mold, for casting purposes, is prepared at a first station and then moved forward. [56] Reerenm cued At a second station on the conveyor, the mold is vibrated and UNITED STATES PATENTS filled with concrete, and then moved forward. At a third station, the concrete is completely sealed within the mold, and 1,574,565 2/l926 Ferguson ..25/41J the mold is elevated, removed from the conveyor rotated 1.736.363 11/1929 Ranjsden x returned to the conveyor, and stripped from the casting. 2,293,446 l0/1942 white 25/120 Ux The casting is then moved along on the conveyor for storage. 2,394,228 2/1946 Barber et al..... 25/41 J UX 3,223,224 12/1965 Fotsch et a1 198/33 X 12 Claims, 13 Drawing Figures PATENTEDMAYZ I972 3,659 986 SHEET 18F 4 4 4 r/M/v Z. GZZBMA/V INVENTOR.

PATENTEDHAY 2 I972 SHEEI i if 4 INVENTOR.

BY J W f/"vy A 50 m APPARATUS FOR MAKING CONCRETE PRODUCTS This invention relates to assembly-line production of cast products, and stated more specifically, it pertains to an arrangement of several known components, along with new apparatus, to mass produce relatively large concrete products.

An object of the invention is to provide fast, practical and efficient equipment to manufacture both structural and nonstructural concrete items, such as floor and wall panels.

An important result of this new development is the reduction in production time per unit cast, as compared to the production time required with present methods and machines.

The new apparatus was designed to produce concrete products in three main stages, or at three primary stations. At a first station, a mold composed of several parts, is assembled and prepared. At a second station, the concrete is placed into the mold and vibrated, and at a third station the product is removed from the mold, or vice versa.

To aid in reducing production time, the various steps or operations take place on, or near to, a conveyor system. An empty mold is placed on one end of a continuous conveyor, the mold is moved along the conveyor intermittently to the several stations mentioned, and the mold and finished product are finally removed at the other end of the conveyor. The conveyor may be any one of several well known roller types, with the rollers interconnected, and driven by an electric motor, in such manner that all rollers start rotating, or stop rotating, at the same time.

A more specific object of this invention is to provide a mechanized unit for lifting a mold from a conveyor, rotating the mold 180, and stripping the mold from the casting therein, all in an exceptionally short period of time.

A new mold vibrating component, along with other novel features of the apparatus, will become apparent, to those skilled in the art, during a reading of the following description, taken in conjunction with the accompanying drawings, in which,

FIG. 1 is a plan view, on a small scale, of the general arrangement of my invention, with a few parts broken away or removed.

FIG. 2 is a perspective view of a palette assembly one part of the mold.

FIG. 3 is a perspective view of a fabricated steel outer frame of the mold.

FIG. 4 is a vertical transverse section thru any one of the conveyor sections, and illustrates a motor for driving the conveyor rollers.

FIG. 5 is a vertical longitudinal section taken on line 5-5 of FIG. 1, with the mold shown in elevation for simplicity.

FIG. 6 is a vertical transverse section taken on line 66 of FIG. 5, and shows a hopper for delivering concrete, added to the view.

FIG. 7 is a perspective view of a wood palette closure plate, which is another part of the mold, and a portion is broken away.

FIG. 8 is a perspective view of the apparatus provided in the vicinity of station three of the invention, with some parts omitted.

FIG. 9 is a vertical longitudinal section taken on line 9-9 of FIG. 1, with the mold shown in elevation for simplicity, and some parts broken away and omitted.

FIG. 10 is a vertical transverse composite section of the complete mold, drawn to a larger scale. The right hand half of the section shows the position of parts before the mold is stripped from the concrete therein, and the left hand half of the section shows the relation of parts after the mold is stripped from the concrete.

FIG. 11 is an elevational view taken on line 1111 of FIG. 1, with some parts broken away.

FIG. 12 is a sectional plan view, on a larger scale, taken on line 12-12 ofFIG.1l.

FIG. 13 is a sectional plan view, on a larger scale, taken on line l3 13 of FIG. 11.

Referring to the drawings, a conveyor is designated as a whole by the numeral 10; a mold, as a whole, by the numeral 1 1; a complete mold vibrating unit, of which there are four, by the numeral 12; a concrete filled hopper by numeral 13; and a mold lifting carriage, as a whole, by the numeral 14.

Before describing the invention in detail, it will be pointed out in a general manner, what comprises each of the components enumerated in the previous paragraph. The conveyor consists of several sections, 1, 2, 3 and 4, spaced slightly apart, and mounted in end to end relation with each other (FIG. 1). Each conveyor section has a floor mounted base 16 and rollers 17. A roller shaft 19 (FIG. 4) is chain connected, at 20, to a gear reduction motor 21.

The mold 11 comprises three primary parts, namely, a rectangular outer steel frame 22, a palette assembly 23, and a wood closure palette or plate 24.

One complete vibrating unit 12 (FIG. 6) includes a power operated vibrator 25, a pair of opposing jaws 26 and 27 arranged to engage the mold 11, a pair of lever arms 28 and 29 connecting the jaws 26 and 27, respectively, to the vibrator 25 at pivot 30, and a solenoid 31 carried by arm 29 and flexibly jointed, at 32, to arm 28.

The hopper 13 has an upwardly open casing 33, a spout 34 at its lower forward end, a small manually controlled door 35, a feed screw 36 for delivering wet concrete to the spout 34, a gear reduction motor 37 mounted on the rear end of casing 33, and a link chain 38 operatively connecting the feed screw 36 to the motor 37.

The mold lifting carriage 14 (FIG. 8) is substantially "C" shaped, or three sided in general conformation. It has two parallel end portions or sides 39 and 40, and an intermediate side 41 rigidly connecting the two end portions. A plurality of wheels 42 are mounted at each end of the carriage, to allow it to roll on a factory floor 43. The carriage is connected to a floor mounted engine 44, of the reciprocating piston type, by a push-pull rod 45 and a yoke 46. Rigidly secured to, and extending upwardly from the carriage frame, is a pair of lifting jacks 47.

The various details of the apparatus will now be pointed out, along with a description of the operation of the invention. As previously stated, at a first station on the conveyor 10, a mold is assembled and prepared. The palette assembly 23, a part of the mold, comprises a steel plate 52 (FIG. 2) having a number of cores 53 fixed thereto. Cores 53 may have various shapes and thicknesses. These cores provide the panel portions of the finished casting. The plate 52 is of a size to fit snugly within the steel frame 22 and seat on the bottom of the frame, thus closing off the bottom portion of mold 1 l.

The mold frame 22 (FIG. 3) has a pair of longitudinally disposed support legs 54 and 55, at its underside, arranged to seat on the rollers 17 of the conveyor. These legs, which are beam shaped, are spaced inwardly an equal distance from the long sides of the frame 22, and are spaced apart from each other. At the bottom of the frame, several spaced cross braces 56 are fixed to the long sides of frame 22 and the legs 54 and 55. These cross braces 56 aid in supporting the palette assembly 23 in the mold. Rigid with the frame 22 and projecting outwardly from the midpoint of each end thereof, is a short shaft 57. These shafts have a common axis that normally falls in a vertical plane thru the center of the conveyor.

Many of the mold units, either identical or diflerent in shape and design, are prepared in advance and centered on the continuous conveyor. As a final step at the first station on the conveyor, material for surface finishes, material for insulating purposes, etc., is placed over the palette assembly, or over the top surfaces only of the cores 53. Such material will thus be cast into and become a part of the finished product.

A steel reinforcing cage 61 (FIG. 10), required for strengthening the concrete product, is now put into the mold. Also any required fasteners and furring strips (not shown) are placed in the mold.

Conveyor sections 1 and 2 (FIG. 1) are actuated and the mold frame 22 and palette assembly 23 move from conveyor section 1 to conveyor section 2. Stopping the mold at a particular place on the conveyor system is controlled by limit switches, or photo-electric cells, and since such practice is common in industry, these items are not shown here.

The upwardly open mold is now at the second station and on conveyor section 2. The apparatus relating to stage two of production, is best illustrated in FIG. 5 and FIG. 6. Wet concrete is placed into the mold at the same time as the mold is being vibrated. When movement of the mold is stopped on conveyor section 2, the mold lies directly over two pairs of vibrator units 12. Each pair of vibrator units is secured to a channel member 58, and spaced a short distance inwardly from each end of the mold. The channels 58 are fixed to the base 16 of conveyor section 2. Each pair of vibrators 12 is located midway between the two nearest conveyor rollers 17 (FIG. 5). The vibrator units are disposed so that each pair of jaws 26 and 27 can be locked to, and unlocked from, the bottom flanges 59 and 60 of the mold legs 54 and 55. Each pair of jaws 26 and 27 open toward each other, or face each other, and they engage or disengage the edges of the flanges 59 and 60, upon activating and inactivating the solenoids 31. In FIG. 6 the jaws are shown locked to the legs 54 and 55 of the mold. A solenoid stroke of only a few inches is needed, to separate a pair of jaws and thus disengage the vibrators 25 from the mold.

The hopper 13, containing ready-mixed concrete of low slump, is moved into a position above the mold, so that the hopper spout 34 is directly over the mold. The solenoids 31, and then the vibrating units 12, are activated, causing the jaws 26 and 27 to grip the mold, and the mold to vibrate. The hopper door 35 is opened by means of a lever 62, the feed screw 36 is put in motion, and wet concrete is now delivered from the hopper spout 34 into the mold. The hopper is suspended by a hoist, and the concrete is placed to all areas of the mold, until the mold is full, by manually guiding the horizontal travel of the hopper 13 with the use of a hand rail 63. Excess concrete, which is the concrete above the horizontal plane at the top edge of the mole, is removed by screeding.

To absorb the shock imparted by the vibrators, the conveyor rollers 17 are preferably made of solid hard rubber on a steel shaft, but cylindrical type rollers having a cushioning surface may be used.

Conveyor sections 2 and 3 are activated, and the mold frame 22, the palette assembly 23, and the poured concrete move from conveyor section 2 to conveyor section 3. At this point, any desirable surface treatment of the casting, such as a rake design, spraying, marbleizing, etc., can take place. The apparatus relating to stage three of production, is best illustrated in FIG. 7, FIG. 8 and FIG. 9. At the third station on the conveyor system, the operations begin by completely and tightly enclosing the still wet concrete, within the mold unit. The wood palette or plate 24 (FIG. 7) comprises a top and bottom piece of plywood 64, slightly larger than the area of the top surface of the concrete in the mold, end reinforcement 65 and cross braces 66, all made of wood. This closure plate 24 is placed over the concrete, aligned and in contact with the top surface of mold frame 22. The plate 24 is then clamped to the mold frame.

Three spaced latches or clamps 67 are provided on each of the long sides of mold frame 22. They are simultaneously actuated by a rod 68. The rod 68 is mounted in bearings 69 on the frame 22, and can be turned in the bearings by means of a handle bar 70, to lock and unlock the closure plate 24 to the mold frame 22.

At the location of the mold on conveyor section 3, each of the short shafts 57 on the mold frame 22, is disposed over a space between conveyor sections. Directly under each shaft 57 is a lifting jack 47 for elevating the mold a few inches above the conveyor rollers, and conversely, for lowering the mold from its elevated position back to its previous seat on the rollers. Each jack 47 is located at the approximate midpoint of one of the end portions 39 and 40 of the carriage, and includes a cylinder 48 (FIG. 9), a piston 49, a vertically disposed piston rod 50, and a bearing 51 on the upper end of the piston rod. The top surface of bearing 51 is preferably of V" shape. The pistons 49 of jacks 47 are pressure fluid operated, and the mold is raised or lowered by means of the piston rods 50, and the bearings 51 which engage the underside of shafts 57. The lifting jacks function simultaneously, and after the mold 1 l is clear of the conveyor, the mold is suspended in a horizontal substantially balanced position.

The jacks 47 are carried by and secured to the movable carriage 14. The carriage end portions 39 and 40 are channel shaped in cross section, and between the sides of each channel end are mounted three spaced wheels 42, the center wheel being located under the lifting jack. The carriage 14 can be moved laterally from its position under the conveyor to a location spaced a few feet from the conveyor, by means of the pressure fluid operated engine 44, the rod 45, and the yoke 46. This travel of the carriage, which is normal to the center line of the conveyor, is just sufficient for the mold 1 l, on the jacks 47, to clear the conveyor by several inches. Should it be preferred, workman can roll the carriage away from, and back to the conveyor, as a substitute for the engine 44.

At its new position, away from the conveyor, the mold unit 1 l, with the concrete therein, is now manually rotated as can be seen in FIG. 8, about its longitudinal axis, while it rests on the lifting jacks 47. The wood closure plate 24 is now on the bottom of the mold unit, instead of at the top. The engine 44 is actuated to return the mold to the center of the conveyor and the carriage 14 to its original location.

It should be pointed out, that the predetermined stroke of engine 44 limits the length of travel of the carriage 14. A tubular channel like element 71, having a continuous slot 72 in one side, is secured to each end of conveyor 3, and projects beyond the carriage side of the conveyor. A small roller 73, on a shaft 74 at each end of the carriage 14, rides in one of the tubular elements 71. This mechanism maintains the carriage in the same straight path of travel.

The jacks 47 are actuated to lower the elevated mold a few inches onto the rollers 17 of the conveyor. The wood closure plate 24 is now contacting the rollers. The legs 54 and 55 of the mold are now at the top of the mold unit II. The clamps 67 are released by means of handle bar 70, and the wood closure plate 24 is thus unlocked from the mold frame 22.

The jacks 47 are again actuated, this time to vertically lift or strip in one operation, the steel frame 22 and palette assembly 23 from the undried, but firm, concrete casting. The concrete product, because of its relative weight, remains on the wood palette 24. Stripping of the frame 22 and palette assembly 23 is not instantaneous, but instead, it is done in what may be described as immediate succession". The steel frame 22 takes the palette assembly 23 with it by means of a lost motion connection. To explain this action, reference is made to FIG. 3 which shows the location of six bolts 75. Looking now at the disclosure in the right half of FIG. 10, wherein the mold steel frame is shown as a channel 18, it will be seen that bolt 75 connects the palette assembly 23 to the steel frame 18 at the intersection of legs 54 and 55 with the cross braces 56. The nut 76 and lock nut, are not pulled up tight. Instead, lost motion space 77 of about 1 inch remains between the nut 76 and bottom flange of leg 54. Referring to the left half of FIG. 10, it will be seen that the mold frame 18 and palette assembly 23 are separated from each other, at 91. Frictional contact keeps the palette assembly 23 stuck to the concrete, until the steel frame 18 has travelled upwardly about 1 inch. The nut 76 then engages the bottom flange of the leg 55, breaking the bond between the palette assembly 23 and the concrete, and the palette assembly then moves upwardly along with the mold frame 18.

The carriage l4 and mold are again moved away from the conveyor by actuating engine 44. Conveyor sections 3 and 4 are now actuated, and the cast product, resting on the plywood plate 24, moves along on the conveyor to storage or kiln treatment. Except for cleaning the stripped mold, the operations at stage three are now finished.

In order that the new structure can be used with some types of pressure fluid lifiing jacks, auxilary equipment is added to the apparatus described above. This added equipment is shown in FIG. 11, FIG. 12 and FIG. 13 and the purpose of this mechanism is to stabilize the piston rods of the jacks and also synchronize the travel of the jack piston rods. On each end 39 and 40 of the carriage 14, a pair of spaced vertically disposed, channel shaped guides 78 are fixed at their bottom ends to the carriage, and also braced thereto at 79. The left hand portion of FIG. 11 is in section, and a right hand part of FIG. 11 is in elevation.

Interposed between the short shaft 57 on the mold l1 and the pressure fluid actuated lifting jack 47, is a tubular frame 80, arranged to travel vertically in the guides 78. This frame 80 includes a top member 81, a bottom member 82, and two side members 83. Secured to the top member 81 is a bearing 51 having a V-shaped upper surface 84 for engaging the underside of shaft 57. The bottom member 82 of the frame 80 has a hole 85, permitting the piston rod 50 to pass therethru. The upper end of the piston rod 50 is connected to the frame 80 so that the frame moves up and down with the piston rod.

A rack 86, fixed to side 83 of the frame, is mounted to engage and rotate a gear 87 secured to a horizontally disposed shaft 88. The shaft 88 is supported in a bearing 89 fixed on the guide 78. The shaft 88 extends to the opposite end of the carriage (FIG. 1).

The structure shown in FIG. 13 is similar, but opposite hand, to that shown in FIG. 12, and is arranged at the other side 83 of guide frame 80. A shaft 90 is relatively short, and only of sufficient length to carry the gear 87 and be supported in the bearing 89. The equipment shown in FIG. 11, FIG. 12 and FIG. 13 is provided on the other end 40 of the carriage. The channel guides 78 as disposed, serve to stabilize the piston rods 50. The gearing and rack arrangement along with connecting shaft 88 function to synchronize the travel of the piston rods.

While the apparatus described above is most efficient when used in three stages of operation, it should be understood that this new development may be used to manufacture cast products at two, or even one station or location.

The invention is shown and described in relation to the manufacture of concrete products, but its use may be adapted to the field of plastics and other arts, and such changes can be made without departing from the scope of the following claims.

I claim:

1. In apparatus for making concrete products, a conveyor mounted on a floor, an upwardly open mold on said conveyor having shafts projecting from opposite ends thereof, means for depositing wet concrete into said mold, means for closing the upwardly open portion of said mold, a lifting jack arranged to engage and disengage each of said shafts for elevating and lowering said mold relative to said conveyor, and a floor mounted carriage partially beneath said conveyor for supporting said lifting jacks and arranged to travel on said floor to laterally remove said mold from said conveyor.

2. The subject matter set forth in claim 1, wherein said mold comprises a plurality of parts, and said lifting jacks are adapted to strip at least two of said mold parts from the concrete therein while on said conveyor.

3. The subject matter set forth in claim I, wherein said mold comprises a plurality of parts, and said lifting jacks are adapted to strip, in immediate succession, at least two of said mold parts from the concrete therein.

4. The subject matter set forth in claim I, wherein said carriage includes a substantially three sided, horizontally disposed frame having wheels contacting said floor.

5. The subject matter set forth in claim- 1, wherein said carriage is provided with a wheel located directly under each of said jacks.

6. The subject matter set forth in claim 1, with the addition of ower operated means for moving said carria e.

. The sub ect matter set forth in claim 1, M the addition of mechanical guide means for maintaining said carriage in a single line of travel.

8. Apparatus for making concrete products comprising, a continuous conveyor having a plurality of conveyor sections mounted on a floor in end to end relation with each other, each of said conveyor sections being individually power operated, an upwardly open mold on one of said conveyor sections, said mold having shafis projecting from opposite ends thereof, means for moving said mold from one of said conveyor sections to another of said conveyor sections, means for depositing wet concrete into said mold, means for closing the upwardly open portion of said mold, a lifting jack arranged to engage and disengage each of said shaft for elevating and lowering said mold relative to said conveyor, and a floor mounted carriage partially beneath said conveyor for supporting said lifting jacks and arranged to travel on said floor to laterally remove said mold from said conveyor.

9. The subject matter set forth in claim 8, wherein said carriage includes a substantially three sided, horizontally disposed frame spaced slightly above said floor, and having wheels contacting the floor.

10. The subject matter set forth in claim 8, wherein each of said jacks is stabilized by vertically disposed fixed guide elements on said carriage.

11. In apparatus for making concrete products, a conveyor mounted on a floor, an upwardly open mold on said conveyor having shafts projecting from opposite sides thereof, means for depositing wet concrete into said mold, means for closing the upwardly open portion of said mold, a power operated lifting jack beneath each of said shafts, each of said jacks being arranged for vertical travel and adapted to engage and disengage said shafis for elevating and lowering said mold relative to said conveyor, interconnected rack and gear mechanisms for synchronizing the travel of said jacks, and a carriage partially beneath said conveyor for supporting said jacks and arranged to travel on said floor to laterally remove said mold from said conveyor.

12. The subject matter set forth in claim 11, with the addition of upright fixed guides for laterally stabilizing said jacks. 

1. In apparatus for making concrete products, a conveyor mounted on a floor, an upwardly open mold on said conveyor having shafts projecting from opposite ends thereof, means for depositing wet concrete into said mold, means for closing the upwardly open portion of said mold, a lifting jack arranged to engage and disengage each of said shafts for elevating and lowering said mold relative to said conveyor, and a floor mounted carriage partially beneath said conveyor for supporting said lifting jacks and arranged to travel on said floor to laterally remove said mold from said conveyor.
 2. The subject matter set forth in claim 1, wherein said mold comprises a plurality of parts, and said lifting jacks are adapted to strip at least two of said mold parts from the concrete therein while on said conveyor.
 3. The subject matter set forth in claim 1, wherein said mold comprises a plurality of parts, and said lifting jacks are adapted to strip, in immediate succession, at least two of said mold parts from the concrete therein.
 4. The subject matter set forth in claim 1, wherein said carriage includes a substantially three sided, horizontally disposed frame having wheels contacting said floor.
 5. The subject matter set forth in claim 1, wherein said carriage is provided with a wheel located directly under each of said jacks.
 6. The subject matter set forth in claim 1, with the addition of power operated means for moving said carriage.
 7. The subject matter set forth in claim 1, with the addition of mechanical guide means for maintaining said carriage in a single line of travel.
 8. Apparatus for making concrete products comprising, a continuous conveyor having a plurality of conveyor sections mounted on a floor in end to end relation with each other, each of said conveyor sections being individually power operated, an upwardly open mold on one of said conveyor sections, said mold having shafts projecting from opposite ends thereof, means for moving said mold from one of said conveyor sections to another of said conveyor sections, means for depositing wet concrete into said mold, means for closing the upwardly open portion of said mold, a lifting jack arranged to engage and disengage each of said shaft for elevating and lowering said mold relative to said conveyor, and a floor mounted carriage partially beneath said conveyor for supporting said lifting jacks and arranged to travel on said floor to laterally remove said mold from said conveyor.
 9. The subject matter set forth in claim 8, wherein said carriage includes a substantially three sided, horizontally disposed frame spaced slightly above said floor, and having wheels contacting the floor.
 10. The subject matter set forth in claim 8, wherein each of said jacks is stabilized by vertically disposed fixed guide elements on said carriage.
 11. In apparatus for making concrete products, a conveyor mounted on a floor, an upwardly open mold on said conveyor having shafts projecting from opposite sides thereof, means for depositing wet concrete into said mold, means for closing the upwardly open portion of said mold, a power operated lifting jack beneath each of said shafts, each of said jacks being arranged for vertical travel and adapted to engage and disengage said shafts for eLevating and lowering said mold relative to said conveyor, interconnected rack and gear mechanisms for synchronizing the travel of said jacks, and a carriage partially beneath said conveyor for supporting said jacks and arranged to travel on said floor to laterally remove said mold from said conveyor.
 12. The subject matter set forth in claim 11, with the addition of upright fixed guides for laterally stabilizing said jacks. 